diff options
author | Hugh Dickins <hughd@google.com> | 2012-07-11 14:02:45 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-11 16:04:48 -0700 |
commit | f21f8062201fc6361f65de92e758a76375ba8c59 (patch) | |
tree | e15ec62a2167a3fbf6e853fb2445ba13d404cad1 /mm | |
parent | 6b91bf1a3f52f5fdf40f5aaeb09a06b4d49556cc (diff) | |
download | linux-f21f8062201fc6361f65de92e758a76375ba8c59.tar.bz2 |
tmpfs: revert SEEK_DATA and SEEK_HOLE
Revert 4fb5ef089b28 ("tmpfs: support SEEK_DATA and SEEK_HOLE"). I believe
it's correct, and it's been nice to have from rc1 to rc6; but as the
original commit said:
I don't know who actually uses SEEK_DATA or SEEK_HOLE, and whether it
would be of any use to them on tmpfs. This code adds 92 lines and 752
bytes on x86_64 - is that bloat or worthwhile?
Nobody asked for it, so I conclude that it's bloat: let's revert tmpfs to
the dumb generic support for v3.5. We can always reinstate it later if
useful, and anyone needing it in a hurry can just get it out of git.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Josef Bacik <josef@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andreas Dilger <adilger@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Cc: Jeff liu <jeff.liu@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/shmem.c | 94 |
1 files changed, 1 insertions, 93 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 4ce02e0673db..3f696f7d9bac 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1692,98 +1692,6 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, return error; } -/* - * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. - */ -static pgoff_t shmem_seek_hole_data(struct address_space *mapping, - pgoff_t index, pgoff_t end, int origin) -{ - struct page *page; - struct pagevec pvec; - pgoff_t indices[PAGEVEC_SIZE]; - bool done = false; - int i; - - pagevec_init(&pvec, 0); - pvec.nr = 1; /* start small: we may be there already */ - while (!done) { - pvec.nr = shmem_find_get_pages_and_swap(mapping, index, - pvec.nr, pvec.pages, indices); - if (!pvec.nr) { - if (origin == SEEK_DATA) - index = end; - break; - } - for (i = 0; i < pvec.nr; i++, index++) { - if (index < indices[i]) { - if (origin == SEEK_HOLE) { - done = true; - break; - } - index = indices[i]; - } - page = pvec.pages[i]; - if (page && !radix_tree_exceptional_entry(page)) { - if (!PageUptodate(page)) - page = NULL; - } - if (index >= end || - (page && origin == SEEK_DATA) || - (!page && origin == SEEK_HOLE)) { - done = true; - break; - } - } - shmem_deswap_pagevec(&pvec); - pagevec_release(&pvec); - pvec.nr = PAGEVEC_SIZE; - cond_resched(); - } - return index; -} - -static loff_t shmem_file_llseek(struct file *file, loff_t offset, int origin) -{ - struct address_space *mapping; - struct inode *inode; - pgoff_t start, end; - loff_t new_offset; - - if (origin != SEEK_DATA && origin != SEEK_HOLE) - return generic_file_llseek_size(file, offset, origin, - MAX_LFS_FILESIZE); - mapping = file->f_mapping; - inode = mapping->host; - mutex_lock(&inode->i_mutex); - /* We're holding i_mutex so we can access i_size directly */ - - if (offset < 0) - offset = -EINVAL; - else if (offset >= inode->i_size) - offset = -ENXIO; - else { - start = offset >> PAGE_CACHE_SHIFT; - end = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - new_offset = shmem_seek_hole_data(mapping, start, end, origin); - new_offset <<= PAGE_CACHE_SHIFT; - if (new_offset > offset) { - if (new_offset < inode->i_size) - offset = new_offset; - else if (origin == SEEK_DATA) - offset = -ENXIO; - else - offset = inode->i_size; - } - } - - if (offset >= 0 && offset != file->f_pos) { - file->f_pos = offset; - file->f_version = 0; - } - mutex_unlock(&inode->i_mutex); - return offset; -} - static long shmem_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { @@ -2787,7 +2695,7 @@ static const struct address_space_operations shmem_aops = { static const struct file_operations shmem_file_operations = { .mmap = shmem_mmap, #ifdef CONFIG_TMPFS - .llseek = shmem_file_llseek, + .llseek = generic_file_llseek, .read = do_sync_read, .write = do_sync_write, .aio_read = shmem_file_aio_read, |